ICESat

ICESat (Ice, Cloud, and Land Elevation Satellite), also designated EOS/GLAS, is a NASA laser altimetry mission that operated from January 2003 to August 2010. It was launched aboard a Delta II rocket and ended operations on 14 August 2010.^[1][2] The launch date is recorded as 12 January 2003 by NASA GSFC, eoPortal, and the CEOS EO Handbook,^[1][2][3] and as 13 January 2003 in one secondary reference.^[4]

The primary instrument was the Geoscience Laser Altimeter System (GLAS), a lidar operating at 1064 nm (ranging) and 532 nm (atmospheric backscatter) that produced the first continuous laser altimetry record of polar ice sheet elevation change, sea ice thickness, cloud and aerosol vertical structure, and land-surface topography.^[5][2]

ICESat operated in a near-polar frozen orbit at 591 km altitude and 94 degrees inclination. The primary science orbit repeated every 91 days; an 8-day repeat track was used during early commissioning for instrument validation before transition to the operational science cycle.^[1] The spacecraft was built on the BCP-2000 (Ball Commercial Platform 2000) bus, manufactured by Ball Aerospace. NASA Goddard Space Flight Center operated the mission throughout its seven-year life.^[5]